Pressure gauge for internal combustion motors



Jumzs,1sa3. J BNHARD Y l2,122,243

PRESSURE GAUGEA FOR INTERNAL COMBUS'IIO MOTORS Filed. Feb, 18, 1937 Patented June 28, 1938 NlTjED PRESSURE canes ron netrunner. cousv 'rioN morons 2 Claims.

This invention relates to new and useful improvements in a pressure gauge for internal combustion motors.

The invention has for an object the construc' tion of a pressure gauge which is adapted to be substituted for each of the spark plugs of an automobile engine or other engine and to-register the pressure built; up in the cylinders during the running of the engine on some of its cylinders, or during such time when the engine is being turned over, either manually or mechanically.

The` purpose of this test is to locate trouble in the engine, such as excessive leaking pistons and valves.

The invention has for tion of a pressure gauge which is characterized by a tubular member forming a compartment, a pressure valve mounted in one end of the tubular member, and an arrangement for mounting the other end of the tubular member in place of a removed spark plug of the automobile or the other engine.

Still further the invention proposes a novel construction of valve associated with the tubular member so as to hold pressures built up therein. It is thus possible to register the highest pressure without requiring fast reading of the gauge due to rapid fluctuations of the ordinary pressures within a motor cylinder.

Still further the invention proposes an arrangement by which the valves may be temporarily inoperative when desired so that the fluctuating pressures may be examined.

For further comprehension of the invention, and of the objectsl and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.

Inlthe accompanying drawing forming a. material part of this disclosure:-

Fig. 1 is a -side elevational View of a pressure gauge constructed according to this invention.

Fig. 2 is a vertical sectional view of the gauge shown in Fig. 1.

Fig. 3 is a horizontal sectional View taken on the line 3 3 of Fig. 2.

Fig. i is a horizontal sectional view taken on the line lof Fig. 2.

Fig. 5 is a fragmentary vertical sectional View similar to Fig. 2 but illustrating a modification or' the invention.

The'pressure gauge for motors, according to this invention, comprises a tubular member l@ forming a compartment i632'. A tubular bushing an object the construcil is attached on the lower end of the member lil and has a threaded portion I la adapted to engage into the spark plug opening of one of the cylinders of the motor. A tubular bushing .l2 is attached upon the upper end of the member l and is adapted to support a pressure gaugevl. A one Way valve It is mounted within the bottorn bushing il. Another one Way valve l is mounted within the top bushing i2. A three way cock I6 'is associated with the top bushing .for controlling the passage of air to the gauge;

The bushing ll has a reduced end ilb over which the tubular member l@ seats. A pin il is engaged through the tubular member and bushing for attaching these parts together. This pin supports a washer lil' which serves as a stop for one end of a coil spring ida. The other end of spring lila presses against the valve ball lil. A valve seat i8 is mounted within the bushing il and the valve tl comprises merely a sphere adapted to seat upon one end of the seat member it. The valve Hl is limited in the distance it may move ofi the seat by the spring ita. The valve Ell permits pressure to pass upwards into the compartment llla and prevents backwash or' the pressure.

The bushing l2 is formed with a reduced portion i2a over which the top end of the tubular member lil engages. A valve seat i9 is supported upon the bushing l2 and the valve l5 is cooperative with this seat. Pins engage through the tubular member i@ and the bushing l2 for connecting these parts together. A coil spring l5 is provided to press the valve ball l5 against valve'seat i9. The top end of the bushing l2 has a threaded bore 2l into which the pressure gauge i3 may be engaged. The details of the pressure gauge are immaterial and therefore Will not be given in this specification.

The cock valve i@ is a three way valve. It controls a vent passage 22 through the side of the bushing i2 into the atmosphere. It also controls a passage 23 from the tubular member lll through the bushing to the pressure'gauge i3. The cock l@ when in the position as shown in Fig. 2 has the tubular member l@ and the gauge i3 connected with atmosphere. It may be rotated through 90 or 180 to control the-pressure as desired. The purpose for having the two valves lil and l5 with the chamber lila interposed therebetween is to prevent fluctuations of the engine from directly acting upon the gauge i3 to cause rapid changes in the gauge preventing it from being read properly. With each explosion of the engine a fast sharp moving pressure is set sure gauge. When this sharp moving pressure passes the valveflidand enters the chamber |02.

it has ample spacewithin which to lose its jerky motion-and smooth out before passing the valve I5 to enter the gauge I3 atan even pace to per-A mit the gauge to accurately measure its velocity.

. valve I4 lifts to permit the pressure to enter,

but prevents exit. As the pressure is being built up'in the compartment la the valve l5 will lift and permit the pressure to reach the gauge i3. In

order to do this it is necessary that the cock I6 be in a position turned from the position shown lnVFig. 2. The gauge I3 will -`how the maximum pressurel produced in the cylinder of the engine. 'I'he cock i6 may then be turned to release the pressure withinJ the compartment IUS and the` gauge which then discharges into the atmosj A f mosphere, each tubular bushing having a rephere.

In' Fig. 5 a modification of the invention has been disclosed in which an arrangement is provided tojhold the'valves inoperative so that the fluctuating pressure within the cylinder may be examined. The arrangement4 consists in each of the valves` I 4 and I5 being provided with a depressible plunger 24 arranged to hold the valves against the'side wall ofthe tubular bushing; and so, inoperative. The plunger 26 is normally urged into an inoperative position by a spring 25 -which acts against a. flange 26. formed on the plunger'Z and a'plug 2l mounted upon the bush-r,

ing. A packing gland 28 is. also associated with the plunger 24 -to prevent leakage of pressure. The plungers 2t normally extend to the exterior so that they may be depressed.

The operation of the modiiled form of the invention is identical to the 'preferred formexcept for the fact that one or both of the plungers 24 may be manually depressed for incapacitating one or both of the valves-the valves I4 and i5.-

The gauge will now show the uctuating pressure which maybe examined with necessary instruments, or the naked eye.

Another test for the internal combustion motor would be to remove all ,of the spark plugs at one time and to substitute pressure gauges as described in this invention for each of the spark plugs. It -is then necessary that the motor be manually turned over or mechanically turned over for ascertaining its condition.

up which would cause sharp changes in the pr While I have illustrated end described the preferred embodiments of my invention, it is to be4 in the appended claims. l

Having thus described `my invention, what claim as new, and desire to secure by United States Letters Patent is:-

1. A pressure gauge for internal ,combustion engines or the like, comprising a. tubular member forming a compartment, ua tubular bushing attached on the lower end of said compartment and threaded for engaging into the spark plug opening of one of the cylinders of said engine, a tubular bushing attached on the upper end of said tubular member and adapted to support a pressure gauge, a one way valve in the bottom bushing for controlling the entrance of pressure into said compartment, a. one way valve in said topbushing for controlling the entrance of pressure from said compartment to said pressure gauge and so prevent the transmission of possible uctuations, and pressure inv said compartment, and a three Way cock valve for controlling said pressures to connect with said gauge or with at- '-forming -a compartment, a tubular bushing attached on the lower end of said compartment and -threaded for engaging into the spark plug opening of one of the cylinders of said engine, avtubular bushing f attached on the upper end of said tubular member and adapted to support a pressure gauge, a one way valve in the bottom bushing for controlling the entrance of pressure into said compartment, a rone way valve in said top bushing for controlling the entrance of pressure from said compartment. to said pressure gauge and so prevent the transmission of possible iluctuations, and pressure in said compartment, and a three way cock valve for controlling said pressures to connect with said gauge or with atmosphere,l each tubular bushing havingareducedv portion over which the ends of the tubular member engage, apin/ engaged through these ends for holding the parts together, and a plate on said pin against whichsaid valve abuts for acting as a stop for said valve.

JOHN BONHARD. 

